With the first puff of a cigarette, nicotine instantly goes to work on the user's nervous system, packing a fast and powerful punch, according to the National Cancer Institute (NCI).

With that powerful pull, it's no wonder people find it so hard to quit smoking. But people do quit -- each year, 3 million Americans give up smoking for good.

If you smoke now, you can beat the habit, too. How? Most experts agree that there's only one successful way: cold turkey.

That means you don't pick up a cigarette. You don't play games with it. You don't put a cigarette between your lips to soothe yourself. You don't keep a pack around the house to show how strong you are. Instead, you throw away the cigarettes and get rid of the ashtrays.

Here are tips from the NCI to help you quit smoking and get through those times when the craving hits:

You can buy nicotine patches, gum and nasal sprays over-the-counter at most drugstores. These products are designed to help you survive the worst period of early withdrawal from addictive nicotine. Check your pharmacy benefits for coverage of these products.

Remember that the psychological aspects of your addiction will be even more difficult to confront than your physical dependence on nicotine. Find ways to change your cigarette-related behavior. If you're used to having a cup of coffee and a cigarette in the morning before work, for instance, switch to tea. Do you light up every time you get in the car? Have a carrot stick instead.

Map out a strategy for dealing with attacks of craving. Figure out what you'll do when you feel the urge to smoke. Call a friend or a hotline or take a walk. Remember that if you can just get through the next 15 or 20 minutes, you will have come through the worst of the craving.

When it gets really tough, remember that you're not alone. Statistics show that 87 percent of smokers wish they could quit.

If you fail a few times, don't despair. Most people who manage to quit permanently have already failed three or four times. So if you don't make it the first time, keep trying!